Method of treating wood pulp fibers and paper product made therefrom



Patented July 28, 1-931 UNITED STATES PATE NT OFFICE JUDSON A. DE GEW', OF MOUNT VERNON NEW YORK, ASSIGNOR TO PROCESS ENGINEERS,

INC OF NEW YORK, fN. Y., A CORPORATION OF NEW' YORK mn'rnon or mna'rme woon PULP rnmns Ann rarnn rnonuc'r MADE 'rnnnnrnou Ho Drawing. Application filed, September.19,- 1929, Serial No. 393,845, and in. Canada February 14, 1929.

In the manufacture of newsprint paper, which consists essentially of a mixture of ground wood and sulphite pulp formed into a sheet of paper, there is an important manufacturing problem resultin from the tendency of these pulps to 'stic k to presses and wires of the paper machine because of certain resinous material in the pul s. When this happens, the pitch coming rom these pulps accumulates on the moving wires and it isnecessary to close down the machine and clean the wires by hand labor, resulting in considerable expense and loss of production.

Wood'that is used for newsprint ulp often contains various proportions of balsam or jack pine mixed with the s race and these woods contain a considera le quantity of,

resinous material. Spruce contains less resin than anyother wood that is usedfor themanufacture of newsprint but sometimes this contains enough resinous material to cause difliculty; Jack pine is awood which could be used in the manufactureof news rint if the resins could'be dissolved in the phite-processor if the pulp made from it without removing the resins, could be mechanically in the manufacture of pape' 'lhe resinous material is not injurious to e pgper but is an ingredient whlch causes diflic ty in the -fi 1,1745697, I described an emulsion made manufacturing process. Y

Sulphite pulp from p will contain portions bfQ-this resinous niaterialin a globular form and'a portion; pfggthi washes out of the pulp. and onto the {pa er; machine clothing consisting of felts an wires) and sticks to t ese fabrics.

Ground wood made from fresh wood also contains sticky resinous .material. Many methods have been .tried' to remove this trouble-but as long as the ,WOOdS carry variable quantities of this resin, the trouble is likely to reoccur regularly in many mills.

The pitchy matter found in ground wood or sulphite pulp does not act as a sizing agent of the fibers insp'ots.

. paper is to change the resinous globules from a condition that is adhesive to one that is not adhesive, and at the same time to produce a paper that wouldnot be classified as a sized paper. In. order to accomplish this I- usea lubricating emulsion of wax or' oil 'whichwill surround or cover the resinous globules so that they will not adhere to the fabric of the paper machine. If these emulsions are not coagulated in. any way they will be mostly washed away through the paper ma chine wire, but by surrounding the pitchy material they will keep it from sticking tothe various parts of the machine; This is the most desirable method of operating unless machine conditions make it necessary to use some coagulant. By dilution and agitation,

aportion of the emulsion will be fixed on the resinous fibers without any coagulant. There will be no objection to coagulating these emulsions and retaining more of them in the paper if this can be done without coating the fibers in such a way as to produce a sized paper. In my United States Patent No. 1,317,618 I have described a paper product that is made water proof byprecipitating an emulsion'of rosin and wax on the papIer o.

bers. In my United States Patent from rosin and ,wax, which had first been blended together and then emulsified. In these patents and in all other methods .where wax emulsions may have been used in conjunction with pulp fibers, the purpose and result of such application has been the production of a sized orwater roof'product.

present invention difiers from these owing tothe fact that I now use a waxemulsion, that will coat or surround the natural resinous globules with pulp but the wax is" not ermanently emulsified with such resin, or b ended with it by solution and consequently an entirely difl'erent result is obtained by this process than any that has been usd heretofore.

It is well recognized in the art of sizing paper that sulphate of alumina, called alum, is an essential ingredient in paper making. It is the accompanying sizing ingredient that is necessary to use as a coaguant inorder to produce a sized paper. aIts useproduces aslightly acid reaction which makes .the sizingwater i'epellant, whereas, if the sizing remains neutral or slightly alkaline it is not water repellant. The same. applies to the paper fibers so that whenv alum 1s not used a sized paper is not produced.

In OldQlltO use wax emulsions as a lubricant and nota sizing material, it is only nec-. essary to discardthe use of'sulphate "of alumma. Y o

It is not material to the application of my process whether the lubricating emulsions are .coagulatedor not except that if they should be coagulated, by any neutral or alkaline salts that may be preesnt inithe stock, I it will only reduce the amount of emulsion lost in the waste water, and will not produce a sized paper. I may even add a calcium or other neutral salt in order to fix the emulsion on the resinous water.

As an example of the manner in which my process may be carried out, I mix with the waxy material, which is approximately equal to the amount of resinous or pitchy material contained in the fibers. This is generally suflicient to cover the resinous particles so 8 that the portion that comes in contact with the paper machinerwire or felt will wash away without sticking to it.

For ordinary spruce wood, one-half of 1% of wax will be sufiicient to accomplish this result but for very pitchy wood more may be necessary.

Standard newsprint is an unsized paper although some small amounts ofrosin size and alum may be used to improve the finish and retain the fine fibers. Rosin size tends to make the fibers stick to the machine whereasalum has a tendency to remove this sticking. Alum has a corroding effect u on the machine and piping of the mill and oes considerable damage but it is used because no better means isknown to get the paper over the machine at the highest speed with the fewest breaks.

A method that will enable the paper mill" to make a neutral or alkaline paper at the highest possible speed will be of great benefit to the makers of newsprint paper.

If I coagulate the amount of lubricating emulsion with which I cover the pitch, by Y using a neutral salt of calcium ormagnesian or any other neutral salt, the finish of paper will be improved and the fine fibers retained but the paper will not be water repellant or sized. to

either alkaline or neutral and which may be made by any process of emulsification, my invention not being in the method of making wax emulsions but in the method of applying them for a new purpose to produce a new reatch of pulp fibers an amount of emulsified paper containing wax surrounding the nat- I may use wax or oil emulsions that are sult, namely an unsized paper containing wax as a lubricant, covering the resinous matter in the paper.

. While many modifications may be made in carrying out my process, the scope of this invention is intended to cover the use of wax or oil or other lubricating emulsions mixed with paper pulp in a neutral or alkaline condition and either dispersed or coagulated for the purpose of removing the sticky properties of said pulp. The emulsions may be used in any proportion sufiicient to remove any stickiness as long as a sized paper is not produced.

This process is particularly adapted to the manufacture of standard newsprint, the specifications and limitations of which are well known, especially with respect to sizing.

Having now described the invention, what is claimed as new, and for which Letters Patent of the United States-is desired, is

1. A method of making standard newsprint paper which consists in covering the natural resins in the pulp with an emulsion of waxy material.

2. A step in the manufacture of standard newsprint paper which consists in adding a non-sizing lubrication emulsion to the pulp stock while the paper is in process of manufacture.

3. A step in the manufacture of newsprint paper which consists in adding suflicient lubricating emulsion to the pulp stock to keep it from sticking to the paper machines and making therefrom a sheet of unsized paper.

4:. A step in the manufacture of paper which conslsts in adding a lubricatin emulsion to the pulp stock and coagulating the emulsion with a salt that will produce an un-' sized paper. 7

5. A ste in the manufacture of paper which consists in coagulating a wax emulsion in the pulp fibers, with an alkaline salt, and producing an unsized paper.

6. A method of producing an unsized ural resins, WhiChCOIISiStS in coagulating an emulsion containing wax in the pulp by means of an earth salt.

7. A method of treating the natural resinous material in pulp fibers, which consists in 15 depositing over said resins from an emulsion,

a non-sizing lubricant.

8. A method of preventing the natural resins in paper pulp from sticking to the 100 paper machine, which consists in surrounding these resins with an emulsified wax composition without subsequent coagulation by alum.

9. A method of treating the natural resins in a paper pulp which consists in adding to the pulp an amount of waxy emulsion approximately equal to the amount of resins.

10. A method of making an unsized paper containing wax which consists in adding a 1 amas wax emulsion to the paper which will be dispersed and partly coagulated by dilution.

11. A paper product having a non-sizing lubricant coagulated over the surface of its 5 natural resins. r

12. An unsized paper product having its resinous impurities coated with a waxy material. q

13. An alkaline newsprint paper, the paper 10 stock of which has been treated with an alkaline lubricating emulsion during the process of manufacture.

14. A netural newsprint paper which has been treated in the manufacturing process 15 with a netural lubricating emulsion.

15. A paper product containing an amount of waxy lubricant approximately equal to the amount of natural resins in the fiber.

Signed at New York, in the county of Nas- 20 sau and State of New York, this 17th day of September, 1929.

' JUDSON A. DE CEW. 

